I bought EGR Valve & Catalytic Converter for 2002 Pontiac Grand Prix GT 3.8L with 225k on Friday, Saturday I had it installed, I should of done the EGR myself just I'm not good with those things & didn't know if I replaced the EGR before the Catalytic Converter if that would mess anything up one before the other as I don't want to be stranded. Only thing is after those 2 things were replaced it still runs like crap. Suggestions? I've asked around. I've been told to get it hooked up to a computer. I contacted another mechanic in MN & he told me take the throttle body off & clean well & then replace.???

165

Asked by Oct 29, 2012 at 09:53 AM about the 2002 Pontiac Grand Prix GT Coupe

Question type: Maintenance & Repair

I bought EGR Valve & Catalytic Converter for 2002 Pontiac Grand Prix GT 3.8L with 225k on Friday, Saturday I had it installed, I should of done the EGR myself just I'm not good with those things & didn't know if I replaced the EGR before the Catalytic Converter if that would mess anything up one before the other as I don't want to be stranded.  Only thing is after those 2 things were replaced it still runs like crap.  Suggestions?  I've asked around.  I've been told to get it hooked up to a computer.  I contacted another mechanic in MN & he told me take the throttle body off & clean well & then replace.???

8 Answers

2,695

it has 225k miles......

2 out of 2 people think this is helpful.
8,165

you can continue to throw parts, or guess....i'd go with technology, is this the same 3.8 that i answered a question about a couple weeks ago? and are there any indicators on, lights on the dash, check engine, any at all?

209,855

Right, what are the issues that you have?

4,245

is your mass airflow sensor clean, a dirty one will affect the way it runs but not nessecarily set a code.

1 out of 1 people think this is helpful.
165

P1404/P0420 before EGR Valve & Catalytic Converter replaced, now no lights on dash other than abs which is disconnected. It only lunges/revs when I drive up hill, slow down then speed up again(4 roundabouts on way home). Where is the mass airflow sensor? Would I be able to clean or replace mass airflow sensor? Would it be the throttle body? Yes this is the same 3.8L I was asking questions about a week.

12,005

Get your car linked to a dynamic engine monitor by an experienced mechanic. This will give you live feedback. As Robert stated above mass air flow definitely a possibility......Mass air flow sensors are not very expensive. They are very delicate careful when installing....

1 out of 1 people think this is helpful.
Best Answer
4,245

It is on your intake by the filter. unplug it, remove the two screws, there is a little sensor on it held in the airstream that when it gets dirty it insulates is giving the pcm wrong readings about the actual air intake and in turn not giving the engine proper amount of fuel for the amount of air coming in. if it was malfunctioning it would set a code but being dirty it's still working just not accurate. clean off the resistors in the sensor you can use brake clean or you can also get maf cleaner made for doint that. if you're careful you can use a q-tip. reinstall and if that's the problem it should run better and probably use less fuel. just by regular maintance like that i got my 97 grand prix up to 36 mpg on the hiway.

2 out of 2 people think this is helpful.
Best Answer
2,695

could be anything, map, mass air sensor, throttle position, sensor idle air motor, or with the mileage you have a combination of one or all, how are the mechanics of the engine , no worn camshaft, no shot fuel injectors......possibilities are endless, and troubleshooting without the proper diagnostic equipment is a shot in dark at best

1 out of 1 people think this is helpful.
Best Answer

Your Answer

Add photo

Related Questions

Grand Prix

Looking for a Used Grand Prix in your area?

CarGurus has 3,767 nationwide Grand Prix listings starting at $1,995.

ZIP:

Search Pontiac Grand Prix Questions

Pontiac Grand Prix Experts

#1 Js08016
Js08016
Reputation 3,770
#2 Tom Demyan
Tom Demyan
Reputation 2,510
#3 munron
munron
Reputation 2,010
View All

Related Models For Sale

Used Chevrolet Impala
951 Great Deals out of 36,332 listings starting at $884
Used Pontiac Bonneville
668 listings starting at $2,298
Used Chevrolet Monte Carlo
19 Great Deals out of 1,738 listings starting at $1,695
Used Pontiac Grand Am
1,717 listings starting at $1,995
Used Chevrolet Malibu
1,164 Great Deals out of 78,646 listings starting at $2,495
Used Chevrolet Camaro
644 Great Deals out of 39,147 listings starting at $2,995
Used Ford Mustang
693 Great Deals out of 38,145 listings starting at $1,750
Used Nissan Maxima
411 Great Deals out of 25,128 listings starting at $1,500
Used Jeep Grand Cherokee
1,117 Great Deals out of 69,518 listings starting at $1,500

Used Cars For Sale

2008 Pontiac Grand Prix For Sale
13 Great Deals out of 472 listings starting at $1,995
2007 Pontiac Grand Prix For Sale
514 listings starting at $2,000
2006 Pontiac Grand Prix For Sale
7 Great Deals out of 618 listings starting at $2,000
2005 Pontiac Grand Prix For Sale
448 listings starting at $4,000